JP2-123281A and JP1-193080A disclose a multipoint ignition device in which a plurality of electrode pairs constituting ignition gaps are disposed around a cylinder opening portion such that an air-fuel mixture in a combustion chamber is ignited from the plurality of ignition gaps.
According to this device, in comparison with a conventional spark plug that performs ignition only from the center of the combustion chamber, combustion of the air-fuel mixture in the peripheral edge portions of the combustion chamber is promoted, enabling improvements in engine output and fuel economy.